tert-butyl N-tert-butoxycarbonyl-N-[3-ethynyl-5-(4-isopropylsulfonylphenyl)pyrazin-2-yl]carbamate (200 mg, 0.3987 mmol), benzoyl chloride (56.04 mg, 46.28 μL, 0.3987 mmol), TEA (44.38 mg, 61.13 μL, 0.4386 mmol) was added to a solution of dichloropalladium; triphenylphosphane (27.98 mg, 0.03987 mmol) and CuI (15.19 mg, 0.07974 mmol) in degassed THF (4 mL). The reaction mixture was stirred overnight at ambient temperature. The reaction mixture was concentrated in vacuo. The residue was partitioned between DCM and NaHCO3 aq sat. The combined organic extract was dried (MgSO4) and concentrated in vacuo yielding an oil that was dissolved in DCM (10 mL). TFA (1 mL) was added and the mixture was stirred at ambient temperature for 30 min. The mixture was concentrated in vacuo to provide the sub-titled product which was used in the next reaction without further purification. LC/MS m/z 406.1 [M+H]+.
